Large industrial and commercial roofs account for a majority of the large roof assemblies in the United States. These roof structures are generally multi-layered, that is, they generally have in combination a roof supporting structure which is surmounted by a deck, and at least one layer of air or water impermeable membrane, thermal insulation, usually in plank form, and generally a ballast layer. These types of roofs tend to be economical and function quite well as long as there is no break in the water-impermeable membrane.
In the assembly of such roofs, the fastening of the roofing insulation materials to the roof decks provides a source of several problems. Frequently, mechanical fasteners fashioned from metals are readily conductive to cold or heat and this results in condensation on the fasteners over a period of time leading to the deposition of water on the interior of the building.
By far the most egregious problem associated with mechanical fasteners is the fact that they tend to work out (back out) of the roof decks after a period of time owing to the movement of the roof assembly due to wind, people walking on the roof, freezing and thawing and the like.
The devices of this invention work very nicely when the old roof structures collapse in view of the fact that the devices of this invention can be covered with a new roof assembly when the roof is reconstructed, and still function as a hold down device and leak detector.
The devices of this invention eliminate thermal bridging, that is, loss of heat through other than lack of insulation, while the devices of the prior art do not have that capability.